Which of the following code snippets will create a memory manager object?

Which of the following code snippets will create a memory manager object?

A.
$memoryManager = Zend_Memory:=>factory(‘None’);

B.
$memoryManager = Zend_Memoryfactory::None;

C.
$memoryManager = Zend_Memory::factory.None;

D.
$memoryManager = Zend_Memory::factory(‘None’);